Jack Leon Ruby (born Jacob Leon Rubenstein; March 25, 1911 – January 3, 1967) was a nightclub operator in Dallas, Texas. On November 24, 1963, Ruby fatally shot Lee Harvey Oswald, who was in police custody after being charged with the assassination of John F. Kennedy two days earlier. A Dallas jury found Ruby guilty of murdering Oswald, and Ruby was sentenced to death. Later, Ruby appealed his conviction and death sentence and was granted a new trial. As the date for his new trial was being set, Ruby became ill and died of a pulmonary embolism due to lung cancer.Many contend Ruby was involved with major figures in organized crime, and conspiracy theorists widely assert that Ruby killed Oswald as part of an overall plot surrounding the assassination of President Kennedy. Others have argued against this, saying that Ruby's connection with gangsters was minimal at most, or circumstantial, and also that Ruby was not the sort to be entrusted with such an act within a high-level conspiracy.